Ubuntu 8.04 boot fail to Ubuntu 10.04 poor latency

Since I have yet to solve the Ubuntu 8.04 boot up from the HD
Problem.

Perhaps a different tact, try and figure out why Ubuntu 10.04 has
such awful latency performance on this Dell more than 300,000 ns

While Ubuntu 8.04 yields latency checks of Less than 10,000 ns on
the very same machine.

Whats the problem here???

I read some where on this forum that on board video can cause poor
latency performance. I tried plugging in a old PCI video card.

This did improve performance and reduce latency to about 170,000 ns
but this is far from being useful.

What other fixes should I try????

Hello,

I have had the same problem with 10.04, did not have time to solve it and went back to 8.04. There is a thread on the mail list you might like to look at something like "migrating from heron to lucid". Some possible solutions involve the software-based OpenGl as found on the troubleshooting section, also perhaps installing a plain version of 10.04 and then installing emc on that. Good luck and let everyone know how things work out.

Rick G

Still wrestling with the same problems!

Which has inspired me to ask if anyone has attempted to compile a list
of computer make and models that work well with Ubuntu and EMC2
and a list of computers to avoid.

If not such a list could save a lot of wasted time and money.

Here is my contribution to such a list:

Works with
Dell Optiplex GX620, 2.8Ghz Pentium D, Bios A11
Ubuntu 8.04 and EMC2 latency about 28,000 ns

Dose Not work with
Dell Optiplex 320, 3Ghz Pentium D, Bios 1.1.5
Ubuntu 8.04 fails to boot, Ubuntu 10 latency about 300,000 ns

Maybe here is what you are looking for:

wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Latency-Test

I believe that list was started some time ago and is a big help but is more relevant to 8.04.

10.04 and 8.04 have different results on the same computers, 8.04 may work on one and 10.04 may not work, the reverse is probably also true.

Of course when the problem of getting 10.04 to work is found the list may make more sense again...

Rick G

Thanks this is table of computers known to work is very useful information.
When I get this sorted out I will have a go that adding my computer info to the list.

Thanks I will download Ubuntu 8.04.4 and give your work around a try

OK!!!! finally stumbled onto the way to get around the Ubuntu 8.04 HD boot failure.

The work around was inspired by John's suggestion to try installing Ubuntu 8.04.4

Since I did not have Ubuntu 8.04.4 on hand and it would take several hours to down
load. I tried installing Ubuntu 10.04 live CD (which I had ). I let the partitioning
wizard divide the disk in half creating a additional partition and do the stock install.

Then restarted the system, I now have a dual boot arrangement, I select Ubuntu 8.04
and Presto it now boots from the HD like you would expect and works like the other
Dell system.

Thanks to all for the suggestions, tips and info.

PS: This battle is won, but I have yet to win the war.